It was a beautiful dog day afternoon at Nationals Park as four-legged Nationals fans filled the Left Field Mezzanine seats for Saturday’s sold-out Pups in the Park promotion.

Dogs were everywhere — streaming through the centerfield gates, running around the field before the first inning, and featured during all of the Nationals’ usual between-inning entertainment segments from the Dance Cam to theFan of the Game.

So it was no surprise when Teddy Roosevelt entered the field for the 4th-inning presidents race with a dog on a leash.

But this was no ordinary dog. It was a giant Brian Griffin, the dog from The Family Guy. Brian ran along with Teddy to an early lead, but as they ran across the outfield warning track, Teddy let goof the leash, and unleashed Brian on the other racing presidents.

As Teddy sprinted for the finish line, Brian ambushed George Washington, then pushed Thomas Jefferson to the ground; but Abe Lincoln managed to sidestep the big dog, and took off after Roosevelt, passing poor Teddy just before hitting the finish line.